Gas Guage & Tank Sender Problems

Many Gas Gauge problems relate to the Gas tank Ground. Before you check anything else make sure the tank itself or at least the sender itself has a ground to the frame. It may be necessary in some cases to add a wire from one of the sender mounting screws to the frame.

55-57's use a 0 to 30 ohm setup that is not the most accurate arrangement and has not been used since the 50's. If you are having problems with accuracy you can correct this to some degree by adjusting the sender arm. This is a trial and error process that you can do after you are sure that both the gauge and the sender are basically functional. For example if the gauge is reading lower than the amount of gas that you know is in the tank, you would raise the gauge reading by bending the float arm down.

To Check Gas Gauge:

1. Take wire off of tank sender, leave it in the air not touching anything. Turn key on, gauge should go to past full.
2. Touch sender wire to frame {full ground}, turn key on, gauge should read empty.
3. If wiring and tank ground is good then sender is not working.
   If you suspect the wiring this check should repeated by removing wires at gauge.

Trouble Shooting Gas Gauge:

FUEL GAUGE Checklist with Ignition 'ON'.

Gauge pegs itself to the right, above full, some possibilities are:

1. Brown wire is off back of gauge.
2. Poor connection at underdash to tail lamp harness plug.
3. Brown wire is broken between gauge and sending unit.
4. Brown wire is off of the sending unit.
5. Bad tank to body ground.
6. Sending unit is bad.

Gauge pegs itself below empty, some possibilities are:

1. Brown and pink wires are swapped on back of gauge ('55 & '56)
2. Brown and tan wires are swapped on back of gauge ('57)

Gauge reads 'E' all the time, some possibilities are:

1. Brown sender wire is shorted to ground.
2. Sending unit is 'stuck' or defective.

Gauge won't budge when the ignition is turned on, some possibilities are:

1. Pink wire is off of gauge or switch is defective ('55-'56).
2. Tan wire is off of gauge or switch is defective ('57).
3. Gauge is bad.

Gauge 'bumps' but will not read at 'E' or above, it may be:

1. Gauge is bad.